Browse Prior Art Database

Underneath Surface Alignment System for Step and Repeat Exposures

IP.com Disclosure Number: IPCOM000069851D
Original Publication Date: 1978-Jun-01
Included in the Prior Art Database: 2005-Feb-21

Publishing Venue

IBM

Related People

Authors:
Santy, WG Wilczynski, JS [+details]

Abstract

Up to now, the alignment in step and repeat optical projection has been obtained on the front surface of the wafer and has required looking through a layer of resist. Subsequent photolithographic steps made the visibility of alignment marks worse. If new alignment aids were added, the total error would increase.